Central Moments of Traffic Delay at a Signalized Intersection

Abstract

Traffic delay model was developed under a basis of deterministic and stochastic delay components. The latter component was put under D/D/1 framework and therein mean and its variance derived. While the stochastic component was put under the M/G/1 framework, mean and variance derived. Extension on stochastic component and M/G/1 framework was discussed with the usage of compressed queueing processes. Harmonization of the moments of deterministic and stochastic components to obtain the overall central moments of traffic delay has been discussed. Simulation was performed using Matlab for traffic intensities ranging from 0.1 to 1.9. The simulated results indicate that both deterministic and stochastic components are incompatible as the traffic intensity approaches capacity. Furthermore the results indicated that oversaturated conditions and random delay renders the stochastic component in traffic delay models unrealistic. Also, with the ability to estimate the variance of overall traffic delay, it is feasible to integrate the concept of reliability into design and analysis of a signalized intersection.

Keywords: D/D/1 model, M/G/1 model, compressed queueing processes, simulation.